Construction machines such as excavators need to be guided with respect to their working tools and the desired dig elevation when digging a trench or a ditch. Modern electronic sensing instruments are typically used to assist the operator of such excavator machines, but in conventional systems, various different types of sensing components must individually be installed at different locations on the excavator machine itself. Each of those components then must individually be calibrated to the particular machine that it has been mounted to, before the operator can perform any useful tasks.